Users are increasingly obtaining content in digital format, often downloading or streaming that content from a remote service. Because different users or client devices require the content to be in specific formats, for example, the remote service will often perform tasks such as video encoding. For streaming video, a provider will often want to designate places where advertising or other supplemental content should be placed relative to the playback of the video content, such as between scenes or at the beginning of a particular segment. In conventional approaches an upstream generator will place a marker in the stream with a time stamp corresponding to the video frame before which the supplemental content should be displayed. Systems can detect this marker and provide notification at a determined amount of time before that frame is rendered for playback, in order to provide sufficient time to determine and/or render the supplemental content for display. In some situations, however, the markers are placed at, or very close to, the video frame in the playback such that there is insufficient time to ready the supplemental content for display.